Sedimentation structures are measures, which purify the surface runoff with the principle of sedimentation. The separation of solid from rainwater discharge (divided sewer system) can be carried out through:
- grit chamber
- rainwater sedimentation tank
- vortex separator system
The dimensioning of plants, that work with sedimentation is done according to the allowed flow rate. It is necessary to check if the surface is big enough to retain a certain grain size. Not permanently filled plants can be of interest for flood control, howbeit they often offer just a little additional retention volume.